Carburetor for internal-combustion engines



C. BROWN CARBURETOR FOR INTERNAL COMBUSTION ENGINES Oct. 2, 1928.

Filed Sept. 27. 1920 w n 7 y m IIIIIII Patented Get. 2, 19.28.

'CLEMENIJEROWBL; or smmmennm, nNeL ivn.

CARBURETOR r 3 rirrnaiien-comsusrionenemas; 7

Application filed September 27,1920, Serial No. naisa anu in' 'Gr eatiliritai n Sep tember'13, 1919. i

This invention relates to improvements in carburetors.

It is an objectof the invention-toprovide means combined with or forming apart or the throttle valve'for automatically varying the amount o f'additional air which is introduced into the fuelinixture and torend'ei" this admission of air'd'ependent upon th'eposition of the throttle valve. v

It is also anob ectof the invention toclose or open iespect'ively'to a varying degree by means of a. throttle valve an orificewvhich communicates with the atmosphere and which leads to a fuel mixture delivery space.

Another-object of the invention is to improve the construction of athrottle valve in carburetors by simplifying the same; and to.

control-'by-the simplified valve not only the admission of additional air, but also'the 'admissioii'ofruel mixture into 'aiuel delivery chamber. j k N V i I It'is furthermore an ob ect or the invent on to provide a throttle-valve with meansWhere- ,by the residue of the mixture otfiiel remaining from a-iormer operation w thin a fuel delivery chamber may be automaticallyremoved through the suction which is producedby the first'strokes of the engine.

' With these and numerous other objects in view the invention is illustrated in the accompanying drawingand described in therollowing specification: v

Fig.1 is an elevation of the principal parts of a carburetor according to the presentinvention; i

I Fig. 2' a Vertical sectional view through the same;

the carburetor ca-s'ing i. The, plug nis providedwith a vertical channel 5, andthe-fuelafter passing thro gl the channel, enters through'a bushing g-into the lower portion f of the mixture chamber. The bushing is preferably seated in the casing 1' by being pressed against a shoulder through a spring m, so as to avoid the necessity of providing these parts with screw threads; The part 7 of the fuel mixture chamber communicates Fig. dis a sectional vertical view at right ith" a chan'ib'er 6 wliicli-is provided-'with'an opening h forthe admission or air. 7

The'flow of fuel may be regulated by-aine'edle'valve zhaving near its upper-end a thread I ed portion j, which isseated in a screw plug 7,

i passing through the t'op plate 8 of tne casing l. By meansor a: spring 9 betii'een-the plug and a head '10 ofthe needle valve, the latter will always be yieldinglyretained iii adjusted position, but still 'may be rea'dily adjustcdby merely:turning'the-top 1'0 ofthe valve. It will be seen, therefore, that owing to thepro- 'vision of this adjustable 'Ii'e'edle valve the amount of fUGl'WhlCll enters from'the, chamber 1 may beadj'usted entirely independent o'f any adiustment or the other parts or the carb'ure'tor. y 7 The chamber) "communicates throughja channel 11 with a chamber 12of the casing and in which athrottle valve 0, preferably in the form of a strai ht slide or plate, ismovsage 11 into thechainbe'r 12 and upon proper adjustment-of the throttle valve plateyc this mixture will enter a channel a inthe throttle valve andwi'll arrive 111 3 transverse bore Z;

or fuel delivery chamber of said valve" .The Wall of the casing 4 may be provided with a circular flange 13 to receive a delivery pipe (not shown) for coni eyingt-lie fuel mixture to the engine. The opening gO' infthis wall ot the casing l, and which is surrounded by the flange 13; is in oppositionfto the opening 31 in the other wall of-the carburetor to permit thea'irto flow straight'through the carburetor upon-proper "positioning of the Plate-"0. y

"The tlirofttlefvalve plate disshownfto be forceddown by one or more springs 14, which are seated in suitable sockets of thevalve plate,and which are gu ded by 111 63118 ofscrew p ns 16, held ,in the' cover 8hr gthe'casing 45.

A 'cable Z, inaybe'iise d for effecting sliding niovementof the valve plate a, whereby the passage or may :be brought out otlcoin muinioa'tionwith thevpassage 11, which leads froin'thechamber into'the' chamber 12". Any other means may b'eused for eiiecting this displacement or for permitting the throttle valve plate a ordinarily to return to the position in which it is shown in Fig. 1.

One of the walls of the casing i isprovided with an air inlet opening d which'ordinarily 40 v be noticed that the cross-sectional area of this i does not communicate with the fuel delivery chamber b, and the mixture of fuel, therefore, will not be influenced by the additional airwhich may flow through the opening d. If, however, the throttle valve is lowered, to a predetermined point'the chamber b in the same will be brought into communication with the opening (Z and the vacuum or partial vacuum-created insaid chamber through the suction of the engine will be partly relieved through the air which enters through the opening d. It is obvious that this air admis sion opening d remains in communication With the chamber 6 throughout a range of movement of the valve plate 0 beginning from said point. The location ofthe air opening rd may be selected, so that, for instance, it will open into the chamber b whenthe throttle platec is in half closed position, and in the continuedmovement of the throttle valve to complete closing position, indicated in dotted lines in Fig.- '1, this communication-between the opening'cl -and the chamber 6 is obviously maintained. When, however, the throttle valve is then moved to open position, it will 7 froma certain point in its movement begin to coverthe opening 0? and in full open position no air will enter through the opening a! into the chamber 1). V I

The rectilinear displacement of the throttle valve to the position indicated in dotted lines in Fig. 1 would bring the channel a in the valve out of communication with the passage 11 extending from the chamber f. In order,

to maintain, however, the admission of fuel from the chamber f to the chamber 12 at most positions of the throttle valve, a branch groove 6 extends from the channel a in a direction at right angle thereto and on the edge of the throttle plate a, as shown. It will also grooving e varies at different distances from the channel a, the capacity at the different distances being accurately determined to control the quantity of fuel admitted to the fuel de- 7 livery chamber 1). With the progress of the closing movement of the valve plate 0, the cross-sectional area of the grooving e decreases, thereby throttling down the amountof fuel which can enter the delivery chamber 6. This amount offuel reduced in volume may then bereduced in saturation, when as,

. the change of the cross-sectional area of the Y for instance, the air opening (Z also registers with'the chamber 6 of the plate 0.

Owing to' these features of control, to wit,

groove e for restricting the inlet of the fuel mixture, the opening cl, which communicates with the fuel delivery chamber 6, through 8.

relatively large range of movement of the valve, very exact means are provided through which the fuel mixture may be regulated in volumea-nd saturation to make it suitable for the requirements of the engine. It is also obvious, however, thatunder certain conditions, either one of these features of control may be omitted, and still a delicate adjustment of the operativeconditions may be ob-- tained through the movement of the throttle valve which automatically restricts a portion of-the inlet for the fuel mixture.

I claim I 1. A carburetor having a casing provided on opposite walls with openings in alinement with each other, a throttle valve rectilineally movable within said casing and having an opening adapted to aline 'with said first named openings in a predetermined position of the valve, a fuel mixture chamber having a passage communicating with the casing-and the throttle valve having a passage extending from the opening therein'angularly to the direction ofthe movement of the throttle valve to an edge portion of the valve, said throttle valve passage communicating onthe edge portion with recesses of graduated depth adapted to be moved successively into opposition to the passage leading from the fuel mixture chamber and adapted to maintain communication between the fuel mixture chamber and the opening in the throttle valve at any position of said throttle valve.

2. A carburetor comprising a casing with alined openings in opposite walls, a plate communicating with the outer, endof the last named passage in the throttle valve and being adapted to maintain a variable communica* tion between said fuel mixture chamber and said fuel delivery chamber at all positions of the valve and to regulate the fuel passing from the fuel mixture chamber to the fuel delivery chamber. I

h 11(11 witness whereof I have hereunto set my CLEMENT BROWN; 

